package com.summer.servlet;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;

/**
 * 作者:夏天
 * qq:1205232048
 */
public class responseDemo extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 1.要获取下载文件的路径
        //String filePath = this.getServletContext().getRealPath("\1.png");
        String filePath = "D:\\编程\\Java\\Code\\JavaWeb\\javaweb-01-servlet\\response\\src\\main\\resources\\1.png";
        System.out.println("下载文件的路径" + filePath);
        // 2.下载的文件名是什么
        String fileName = filePath.substring(filePath.lastIndexOf("\\") + 1);
        // 3.设置想办法让浏览器能够支持下载我们需要的东西
        resp.setHeader("Content-Disposition","attachment;filename=" + URLEncoder.encode(fileName,"UTF-8"));
        // 4.获取下载文件的输入流
        FileInputStream fileInputStream = new FileInputStream(filePath);
        // 5.创建缓冲区
        int len = 0;
        byte[] buffer = new byte[1024];
        // 6.获取OutputStream对象
        ServletOutputStream outputStream = resp.getOutputStream();
        // 7.将FileOutputStream流写入缓冲区，使用OutputStream将缓冲区中的数据输出到客户端
        while ((len = fileInputStream.read(buffer)) != -1){
            outputStream.write(buffer,0,len);
        }
        // 8.关闭流
        fileInputStream.close();
        outputStream.close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}
